1. Field of the Invention
The present invention relates to an electronic apparatus utilizable in a display device such as a liquid crystal display device, and more particularly to possessing a structure in which an integrated circuit or a tape carrier attached to which an integrated circuit is attached is connected to, for example, a glass substrate of a display panel.
2. Description of the Prior Art
Hitherto, in order to realize reduction of size and lowering of cost of a liquid crystal display device, a method of connecting a tape carrier to which an integrated circuit for driving the liquid crystal directly attached to a glass substrate composing the display panel has been known. FIG. 1 is a sectional view showing the structure near a tape carrier 6 of a conventional liquid crystal display device. Two glass substrates composing the liquid crystal panel are overlapped with an offset. Therefore, one glass substrate 2 possesses a region not overlapping with the other glass substrate. In this region, the tape carrier 6, to which an integrated circuit (not shown) or the like for driving the liquid crystal is attached, is connected. In the overlapping region of the two glass substrates, liquid crystal material or the like is sealed in, so as to effect liquid crystal display in this region.
On the surface of the glass substrate 2, a common conductor 4 for signal input is disposed. On the surface of the tape carrier 6 confronting the glass substrate 2, an input signal conductor 3 and a connecting conductor 7 are formed. This connecting conductor 7 is connected to the common conductor 4 for signal input by way of an anisotropic conductive film 5.
In such connection structure, in the region indicated by reference code A1 in FIG. 1, the input signal conductor 3 on the tape carrier 6 and the common conductor 4 for signal input formed on the glass substrate 2 cross over to form a multilayer conductor structure. Conventionally, to prevent short-circuit of the input signal conductor 3 and the common conductor 4 for input signal, a resist 1 such as an electrically insulating resin was applied on the input signal input conductor 3. By this resist 1, the input signal input conductor 3 on the tape carrier 6, and the common conductor 4 for signal input on the glass substrate 2 are insulated from each other.
In such a conventional device, the tape carrier 6 is deformed in the region indicated by reference code A1. Such deformation of the tape carrier 6 is considered to be caused by a relatively large thickness of the resist 1, and difference in the thermal expansion coefficient of the resist 1 and the tape carrier 6. By such deformation of the tape carrier 6, a stress is caused in the connection part of the common conductor 4 for signal input and the connecting conductor 7. Their may result in a defective connection or the like.
The conductor from the tape carrier 6 to the display region is formed on the surface of glass substrate 2. In such a conductor layout area, it is necessary to arrange conductors at high density by narrowing the conductor clearances. However, if the spacing between conductors is too narrow, due to dew condensation of moisture, defective insulation occurs. Hence there is a limit to the miniaturization of wiring conductors. In addition, in the narrow conductor spacing area, defective insulation due to foreign deposit may also take place.
Meanwhile, in the face-down bonding method of directly connecting the integrated circuit to the glass substrate, the above technical problems are not solved. In this case, moreover, positioning of high precision is required in connecting the integrated circuit to the glass substrate. That is, where the conductor interval is narrow in the connecting part, a slight dislocation may give rise to short-circuit or leak between the connecting electrode of the integrated circuit and the conductor adjacent to the connecting position of the glass substrate. Furthermore, in the case of connection of the integrated circuit directly to the glass substrate, when a conductive paste is used as the connecting material, this conductive paste may be spread widely and unexpectedly when connecting. This may also lead to short-circuit or leak between the adjoining conductors.